As I understand it, you killed enemies on the first level, after which a block fell from behind and you don't know what to do next? You need to get closer there, and then the next level will begin.
And yes, if you did this and nothing happened, then it's probably a problem with exporting from Linux, since I don't have the opportunity to test the game on Linux.
Please install new version
Ok I gave it another try based on your comment and was able to proceed, I had to walk all the way into the wall. I got stuck in a loading loop on the second stage but was able to break out eventually and complete the game (I think) assuming killing the big boss one is the end. Fun concept with tight spaced FPS battles, would have liked to seen more effort on graphics but I think I get the vision.
